Azo dye.



- To all whom it may concern:

UNITED STATES PATENT OF ICE- ERNST ULRICHS, OF ALTER MARKT, ELBERFELD,GERMANY, ASSIGNOR T0 COMPANY WljLFING, DAHL & 00., ACTIENGESELLSCHAFTFARBENEABRIKEN, 0F BARMEN,

GERMANY.

' AZO DYE.

937,741. I Specification of Letters Patent.

No Drawing.

lie it known that l, ERNST Unnicns, a subject of the Kin g of Prussia,German Emperor, and residentof Alter Markt, Elberteld, Province of theRhine, German Empire, have invented certain new and useful Improvementsin r .zo Dyes, of which the following is a specification.

This invention relates to a v (lacing-an azo-dye which shall bespecially suited, for use in the color lake industry. I have discoveredthat if the dye produced ,from diaz-o-naphthylamin-sulfo acid 2.1 and\betamaphthol is treated with a suitable con- (lensing medium thereresults an azo-dye which has certain special advantages in theproduction of color lakes.

The following are some examples of the present invention:

Example 1: 80 kg. of the dried sodium salt (at a temperature of 100" G.)of the dye produced from diazotized naphthylamin- 'sulfo acid 2.1 andbeta-na hthol are mixed with 400 kg. acetic anhydrld. The mixture,

which is of a thin liquid constituency, is

then heated and thereby thickens. When the acetic anhydrid is distilledofi the re-- maining dye weighs 78.2 kg. The explana-' which for brevityshall be called F-anhydrid, there has been found on anaverage anlncrease 111 the content of carbon of i 1.31% (which according to theabove theory should be 1.37%) and a decrease in the content of hydrogenamounting to 0.28% (by theory 18%) over the original dye before thetreatment described. F-anhydrid is distinguished'by the folmethod ofproquantity of carbon and hydrogen- I day of February Patented oct. 19,1909.

Application filed March 9, 1909. Serial No. 422,241.

lowing features :1. It is dark red while the original substance isbright red. 2.v The specific gravity of the new material is considerablylower than that of the original substance. 3. The new dye yields ontreatment with Turkey 'red oil and boiling with This solution is thenslowly poured], while stirring, into a mixture of 9 10 kg. of a so diumlye of {10 B. and 600 liters of a saturated solution of salt in water.The resulting dye-stulf is separated off by filtration and may befurther treated while in the form of a dough or it may be dried.

I claim:-- p

1. The process of producing an azo-d e consisting in treating the dyeproduced from -diazonaphthylamin-sulfo acid 2.1 and betanaphthol with asuitable condensing medium to-separate water! 2. The process ofproducing an azo-dye consisting in treating the dye produced from diazo'naphthylamin P sulfo acid naphthol with acetic water.

The dye derived from diazo-naphthylamin-sulfo acid 2.1 and beta-naphtholunder separatioil of water andeharacterized by aving a dark red colorand, less specific gravity than the dyes of the same derivativesformerly known.

Signed at Barmen, Germany, this 19th ERNST ULRIGHS. [L. s.] Witnesses:

Orro Kome, KARL BAUEIL.

anhydrid to separate and. beta-

